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I've a motherboard that seems dead. I've changed the processor, psu, memory for known working ones and disconnected all non essential peripherals (drives, USB connections).

The light on the motherboard comes on but non of the fans spin up. There are no bleep codes to help diagnose the issue. I've inspected the capacitors on the board to see if there's any obvious leakage or bulging but found no issues.

At what point in POST do the fans come on in your experience? Can I assume that if the fans don't spin then POST isn't even starting?

I should also add I've tested the on button to make sure it's resistance spikes on pressing and also swapped out the cmos battery and cleared the cmos.

One other thing to note is that the psu fan doesn't spin either.

Any feedback or ideas would be much appreciated.

Many thanks

Richard

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Just saw a tumbleweed roll by. –  Rich Aug 28 '12 at 18:37
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2 Answers

When you plug the system in, the fans normally should spin for a fraction of a second, and then stop. If this happens, your motherboard is certainly working in some capacity. If not something is seriously wrong. Typically what the fans do on poweron is spin at max speed until the bios initalizes and slows them down. Early bios or CPU failure can cause the system to fail to do that, giving a system that doesn't post but where the fans run at full speed.

Are you sure you are connecting the power button to the right pins and in the right orientation? You may need to look at the motherboard manual to be sure.

Also if there are fab speed jumpers on the system make sure they are set to a speed your CPU can handle.

Beyond that you need to rma your motherboard. You didn't install the motherboard in the case directly against the metal case, did you? (standoffs are a must)

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Thanks for your response ultrasawblade. The motherboard has been installed on metal standoffs and the power button has been connected in the correct orientation. I'm wondering if that fact that the psu fan doesn't spin when connected to this board means it's detecting a short and cutting either the 5 or 12 volt rails out to prevent further damage? –  Rich Aug 28 '12 at 19:15
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The only way to properly tell what is going on is to use either the post leds built in to the pc or get a post code diagnostic card you plug in to the systemboard. I had 2 msi boards new that were totally dead like that and I didnt have the post reader. Since they were new and had no leds I just had to try a 2nd of every thing then when that was dead I requested a refund and went with a different board which has built in diagnostic leds.

The post testers used to be 30$ not sure if they still are.

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+1 for POST diagnostic board. Thanks Kendrick. Yes, I've been considering getting a POST code diagnostics board. Ordinarily I'd give up on a motherboard like this as the time isn't worth the possible reward, but I've instead decided to deepen my knowledge of motherboard diagnostics and see this one through to a possible bitter end. –  Rich Aug 30 '12 at 10:32
    
I was appaled by the msi lack of any diagnostics... usually you get some beep or flash some where but oh well.. from now on Im only getting systemboards with diagnostics on them. the asrock i have now has a # readout for posting so you can look up the codes plus power and reset buttons built in to the systemboard. Since i tinker a bit its easier on me to have it that way... for example Im putting that board in a Dell 2650 2u case :D –  Kendrick Aug 31 '12 at 0:13
    
for got to mention. did you test a known good psu or that psu on another board? I have seen many a dell not post and even with a simple power supply tester it shows good. put a known good psu in and the pc boots... unless you spend some money for a decent psu tester I would go with known good. you will probably end up playing more for a psu tester then getting a backup psu. bad power can do all kinds of wierd things so check that first when you start having odditys. –  Kendrick Aug 31 '12 at 0:18
    
Yes I've tested the power supply in another machine and it's fine. I'm wondering the value of a psu tester... do you think it would just test the voltages on each of the wires in the power connector or would it suitably load the supply to emulate real useage? BTW motherboard POST diagnostic cards go for around £6 including postage (ebay) these days. I have one on order. I expect it may come in handy in the future. –  Rich Aug 31 '12 at 11:04
    
depends on how expensive it is. The one I have experiance with dell handed out to their dcse tech's and it was garbage. you would need to do some reading of reviews and specs to see if there are any decent ones out there. for my systems I can get a new power supply for about 60$ so id rather have a backup power supply ready to go as a known good then a tester. –  Kendrick Aug 31 '12 at 12:02
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